
Check valves made up of various materials are available in the market. They differ in size, dimension, material, thickness, and surface. Duplex Check Valve is one such valve that is widely available. They are designed using mechanical as well as physical properties which include tensile strength, yield strength, elongation, and so on. Duplex 2205 Check Valves are available in various forms such as flanges end, socket weld, screwed, screwed parallel, and screwed taper. They are available in plates, spools, sheets, and various other forms.
Duplex Stainless Steel Check Valve is used in condensers, heat exchangers, chemical industry, pharmaceutical industry, pulp, and paper industry, petrochemical industry, and power generation industry. Furthermore, duplex check valve manufacturers in India advise these valves to be used in offshore drilling, gas processing, seawater equipment, chemical equipment, and special chemical industries. They are also used in marine applications and oil refineries.
Duplex Check Valve Function is to manage the pressure difference that might arise in the two air springs. When the pressure difference reaches 1.5 gm the valve allows air to flow from one air spring end to the other. The Duplex Spring Check Valve does not require any standard routine maintenance. The piston-type valves are usually used in compressed air breaks systems in railways. The Duplex Check Valve Working can be understood by that of having 2 air ports. When the air pressure in one port is higher than the one in the second port by the set differential pressure then the valve allows the air to flow from the higher port to the lower port to balance the pressure.
| BRAND NAME | TU-LOK |
| VALVE SIZE | 1/8" TO 2" / 6 MM TO 50 MM |
| CONNECTION | THREADED, TUBE END, SOCKET WELD END, FLANGE END |
| THREADS | NPT, BSPP, BSPT, METRIC, JIC, UNF |
| FLOW PATTERN | STRAIGHT |
| MANUFACTURER OF BODY SHAPE | HEXAGON |
| PRESSURE RATING | 1500 PSI, 3000 PSI, 6000 PSI, 10000 PSI, 15,000 PSI, 20000 PSI |
| CRACKING PRESSURE | 0.5 BAR |
| ORIFICE SIZE | 2 MM TO 40 MM |
| MANUFACTURER OF TYPE | POPPET TYPE, SPRING TYPE |
| MEDIA | HYDRAULIC OIL, AIR, WATER, GAS, STEAM, HOT WATER , COLD WATER , SEA WATER , CHEMICAL |
| MEDIA TEMPERATURE | (-50* C TO 350*C ) RANGE AS PER PRESSURE |
| BODY TYPE | BAR STOCK, FORGED |
| PACKING DETAILS | BOX PACKING, WOODEN PALLET |
| EQUIVALENT BRANDS | SWAGELOK, PARKER, STAUFF, DK-LOK, HAMLET, OLIVER VALVES, HOKE |
| MATERIAL | DUPLEX 2205, UR52N+ |
Description |
Price |
| Duplex Stainless Steel F51 Dual Plate Poppet Check Valve | US $ 10-300 / Piece |
| API Duplex Stainless Steel Non Return Poppet Check Valve | US $ 88-288 / Piece |
| Duplex Stainless Steel Butterfly Type Duo Check Valve | US $ 28-189 / Piece |
| 1" Cast Iron Wafer Duplex for Water with Competitive Price Silent Check Valve DN80 | US $ 11-17 / Piece |
Valves Size |
Type |
Cracking Pressure (psi) |
Weight (lbs) |
|---|---|---|---|
| 1/2" | NPT | 0.25 | 1.0 |
| 1/2" | NPT | 5.0 | 1.0 |
| 1/2" | Socket Weld | 0.25 | 1.0 |
| 1/2" | Socket Weld | 5.0 | 1.0 |
| 3/4" | NPT | 0.25 | 1.5 |
| 3/4" | NPT | 5.0 | 1.5 |
| 3/4" | Socket Weld | 0.25 | 1.5 |
| 3/4" | Socket Weld | 5.0 | 1.5 |
| 1" | NPT | 0.25 | 2.3 |
| 1" | NPT | 5.0 | 2.3 |
| 1" | Socket Weld | 0.25 | 2.3 |
| 1" | Socket Weld | 5.0 | 2.3 |
| 1 1/4" | NPT | 0.25 | 3.5 |
| 1 1/4" | NPT | 5.0 | 3.5 |
| 1 1/4" | Socket Weld | 0.25 | 3.5 |
| 1 1/4" | Socket Weld | 5.0 | 3.5 |
| 1 1/2" | NPT | 0.25 | 5.3 |
| 1 1/2" | NPT | 5.0 | 5.3 |
| 1 1/2" | Socket Weld | 0.25 | 5.3 |
| 1 1/2" | Socket Weld | 5.0 | 5.3 |
| 1 1/2" | NPT | 0.00 | 5.3 |
| 2" | NPT | 0.25 | 8.5 |
| 2" | NPT | 5.0 | 8.5 |
| 2" | Socket Weld | 0.25 | 8.5 |
| 2" | Socket Weld | 5.0 | 8.5 |
| 3" | NPT | 0.25 | 21 |
| 3" | NPT | 5.0 | 21 |
| 3" | Socket Weld | 0.25 | 21 |
| 3" | Socket Weld | 5.0 | 21 |

End Connections |
Pressure Rating at 100°F (37°C) |
Series |
Dimensions |
||
Size |
Type |
B |
A |
||
1/8 in .0 |
Fractional tube fitting |
6000 (413) |
CH4 |
11/16 |
2 .027 (57 .07) |
1/4 in .0 |
2 .043 (61 .07) |
||||
3/8 in .0 |
CH8 |
1 |
2 .075 (69 .09) |
||
1/2 in .0 |
2 .096 (75 .02) |
||||
3/4 in .0 |
5000 (344) |
CH16 |
1 5/8 |
3 .052 (89 .04) |
|
1 in .0 |
4700 (323) |
3 .088 (98 .06) |
|||
6 mm |
Metric tube fitting |
6000 (413) |
CH4 |
11/16 |
2 .043 (61 .07) |
8 mm |
CH8 |
1 |
2 .070 (68 .06) |
||
10 mm |
2 .080 (71 .01) |
||||
12 mm |
2 .096 (75 .02) |
||||
22 mm |
4900 (337) |
CH16 |
1 5/8 |
3 .048 (88 .04) |
|
25 mm |
4600 (316) |
3 .088 (98 .06) |
|||
1/4 in .0 |
Female NPT |
6000 (413) |
CH4 |
11/16 |
2 .013 (54 .01) |
3/8 in .0 |
5300 (365) |
CH8 |
1 |
2 .055 (64 .08) |
|
1/2 in .0 |
4900 (337) |
1 1/16 |
3 .003 (77 .00) |
||
3/4 in .0 |
4600 (316) |
CH16 |
1 5/8 |
3 .023 (82 .00) |
|
1 in .0 |
4400 (303) |
3 .083 (97 .03) |
|||
1/8 in .0 |
Male NPT |
6000 (413) |
CH4 |
11/16 |
1 .079 (45 .05) |
1/4 in .0 |
2 .017 (55 .01) |
||||
3/8 in .0 |
CH8 |
1 |
2 .036 (59 .09) |
||
1/2 in .0 |
2 .073 (69 .03) |
||||
3/4 in .0 |
5000 (344) |
CH16 |
1 5/8 |
3 .029 (83 .06) |
|
1 in .0 |
3 .067 (93 .02) |
||||
1/4 in .0 |
Female ISO➀ |
6000 (413) |
CH4 |
11/16 |
2 .028 (57 .09) |
1/2 in .0 |
5100 (351) |
CH8 |
1 1/16 |
3 .029 (83 .06) |
|
3/4 in .0 |
4800 (330) |
CH16 |
1 5/8 |
3 .055 (90 .02) |
|
1 in .0 |
4400 (303) |
3 .083 (97 .03) |
|||
1/4 in .0 |
Male ISO➀ |
6000 (413) |
CH4 |
11/16 |
2 .017 (55 .01) |
1/2 in .0 |
CH8 |
1 |
2 .073 (69 .03) |
||
3/4 in .0 |
5000 (344) |
CH16 |
1 5/8 |
3 .029 (83 .06) |
|
1 in .0 |
3 .067 (93 .02) |
||||
1/2 in .0 |
Female SAE/MS |
4600 (316) |
CH8 |
1 |
2 .074 (69 .06) |
1/2 in .0 |
Male SAE/MS |
4600 (316) |
2 .048 (63 .00) |
||
1/4 in .0 |
Male VCO fitting |
6000 (413) |
CH4 |
11/16 |
1 .098 (50 .03) |
1/2 in .0 |
CH8 |
1 |
2 .035 (59 .07) |
||
3/4 in .0 |
5000 (344) |
CH16 |
1 5/8 |
2 .090 (73 .07) |
|
1 in .0 |
|||||
1/4 in .0 |
Male VCR fitting |
6000 (413) |
CH4 |
11/16 |
2 .028 (57 .09) |
1/2 in .0 |
4300 (296) |
CH8 |
1 |
2 .073 (69 .03) |
|
3/4 in .0 |
3700 (254) |
CH16 |
1 5/8 |
3 .078 (96 .00) |
|
manufacturer of Grade |
A8901A/A995 3A CD4MCu A890/A995 1B CD4MCuN A890/A995 2A CE8MN A890/A995 4A CD3MN |
Standards |
API 6D or ISO 14313:1999 |
Face to Face Standard |
As per ASME B 16.10 |
Testing Standards |
API Standard 594 |
Inspection Standard |
API 598. |
| Valves Size | A | B | C |
|---|---|---|---|
| ½” | 65 | 46 | 19 |
| ¾” | 80 | 58 | 23 |
| 1” | 90 | 69 | 27 |
| 1 ¼” | 105 | 75 | 32 |
| 1 ½” | 120 | 85 | 41 |
| 2” | 140 | 98 | 50 |
All wrapped up Duplex Stainless Steel Check valves are pressed to suit the extraordinary conditions for worldwide conveyances and can too customized as per customer's particular necessities.
| NPS | Weight (lb) | G | d | D | C | H | L | f | T | N | M |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2” | 37.05 | 3.062 | 2 | 5.098 | 4.074 | 5.039 | 8 | 0.006 | 0.063 | 4 | 0.075 |
| 2-1/2” | 50.07 | 4.013 | 2.05 | 7.001 | 5.049 | 5.087 | 8.05 | 0.006 | 0.071 | 4 | 0.075 |
| 3” | 63.09 | 5 | 3 | 7.048 | 6 | 6.034 | 9.05 | 0.006 | 0.075 | 4 | 0.075 |
| 4” | 92.06 | 6.018 | 4 | 9.002 | 7.05 | 9.002 | 11.05 | 0.006 | 0.094 | 8 | 0.075 |
| 6” | 163.01 | 8.05 | 6 | 10.098 | 9.051 | 10.075 | 14 | 0.006 | 1.002 | 8 | 0.087 |
| 8” | 238.01 | 10.063 | 8 | 13.05 | 11.075 | 13.043 | 19.05 | 0.006 | 1.014 | 8 | 0.087 |
| 10” | 390.02 | 12.076 | 10 | 15.098 | 14.025 | 15.087 | 24.05 | 0.006 | 1.022 | 12 | 0.098 |
| 12” | 621.07 | 15 | 12 | 19.002 | 17.001 | 18.054 | 27.05 | 0.006 | 1.026 | 12 | 0.098 |
| Material Construction | ||
| # | Compon.n, | Material |
| 1. | Body | SS 316 |
| 2. | Poppet | SS 316 |
| 3. | Seat Seal | Viton |
| 4. | Spring | SS 316 |
| 5. | Spring Guide | SS 316 |
| 6. | Stopper | SS 316 |
| 7. | Joint Seal | Viton |
| 8. | Adaptor | SS 316 |
ELEMENT |
DUPLEX 2205 |
DUPLEX 31803 |
|---|---|---|
NI |
4.50 – 6.50 |
4.50 – 6.50 |
C |
0.030 max |
0.030 max |
MN |
2.00 max |
2.00 max |
P |
0.030 max |
0.030 max |
S |
0.20 max |
0.020 max |
SI |
1.00 max |
1.00 max |
CR |
21.0 – 23.0 |
22.0 – 23.0 |
MO |
2.50 – 3.50 |
3.0 – 3.5 |
N |
0.08 – 0.20 |
0.14 – 0.20 |
FE |
63.54 min |
63.72 min |
| Grade | YS (MPa) | UTS (MPa) | % Elongation | Hardness(BHN) |
| 31803 | 450 min. | 620 min. | 25 min. | 293 max. |
| 2205 | 450 min. | 655 min. | 25 min. | 293 max. |
| STANDARD | WERKSTOFF NR. | UNS |
|---|---|---|
| Duplex 2205 | 1.4462 / 1.4462 | UNS S31803 / UNS S32205 |
They are commonly introduced in applications that backflow would cause an issue. Be that as it may, since they are non return valves, they are a cheap, viable, and simple arrangement to unravel a potential issue. Backflow can cause an issue on the off chance that the backflow is sullied, and thus, sullies the media upstream.
For illustration, a sewer line will have a non return valve to guarantee that squander can take off but not re-enter the framework. They are moreover utilized in the event that backflow will cause harm to gear upstream that can as it were permit media to stream in one course.
| Indonesia, Philippines, Belgium, Dammam -KSA | Duplex Stainless Steel Poppet Check Valves |
| France, Europe, Thailand, Qatar | Duplex 2205 Lift valve |
| Germany, Thailand, Malaysia, Czechia | Duplex Stainless Steel Wafer Check Valves |
| USA, Bangladesh, Finland, Malaysia | Duplex API Pressure Sealing Valve |
| Saudi Arabia (KSA), Kuwait, Brazil, South Africa | Duplex Stainless Steel Float Ball Check Valves |
| South Africa, Singapore, Singapore, Bahrain | Duplex Steel S31803 Valves |
| Australia, UK, Nigeria, Philippines | Duplex Stainless Steel Flanged Nozzle Type Valves |
| Malaysia, Hong Kong, UAE, Oman | F51 F51 F53 F55 Duplex Stainless Steel Spring Check Valves Non Return Valves |
| Italy, Iran, Singapore, Chile | Duplex Stainless Steel Vertical Lift Check Valves |
| Turkey, Norway, Malaysia, United Arab Emirates (UAE) | Ball Type Direction Non Return Duplex Valves |
| Malaysia, Russia, Dubai, Netherlands | Saf2205 Duplex Stainless Steel Duo Valves |
| Spain, Mexico, UK, Egypt | API Duplex Stainless Steel 6A Lug Valves |
| Europe, Malaysia, UAE, United Kingdom -UK | Duplex Stainless Steel Dual Plate Poppet Check Valves |